CN103700273A

Movatterモバイル変換

Info

Publication number: CN103700273A
Application number: CN201410004750.6A
Authority: CN
Inventors: 陈峻; 顾姗姗; 何鹏; 刘志广
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2014-01-06
Filing date: 2014-01-06
Publication date: 2014-04-02
Anticipated expiration: 2034-01-06
Also published as: CN103700273B

Abstract

本发明公开了一种基于可变导向车道的信号配时优化方法，在可变导向车道功能属性发生变化后，根据检测器获得的各转向交通量，得出各转向车流饱和度，根据饱和度确定不同的信号配时优化方案，具体包括：饱和度较低时，以延误最小作为控制目标，采用传统韦伯斯特法确定周期与信号配时；当饱和度大于0.9时，以提高路口通行能力与减小延误为目标，若某一转向过饱和时，利用爬山法调整周期和绿信比；若各转向均达饱和，在常规四相位基础上增加一个相位，重新划分相位组，寻找各组合相位组的关键相位链，按等饱和度原则分配绿灯时间；达到减小交叉口总延误、提高通行能力的目的。

The invention discloses a signal timing optimization method based on a variable guiding lane. After the functional attribute of the variable guiding lane changes, the saturation of each turning traffic flow is obtained according to the traffic volume of each turning that is obtained by a detector. According to the saturation Determine different signal timing optimization schemes, including: when the saturation is low, take the minimum delay as the control target, and use the traditional Webster method to determine the period and signal timing; when the saturation is greater than 0.9, to improve the traffic capacity of the intersection With the goal of reducing the delay, if a steering is oversaturated, use the hill climbing method to adjust the period and green signal ratio; if all steering is saturated, add a phase on the basis of the conventional four phases, re-divide the phase group, and find each combination The key phase chain of the phase group allocates the green light time according to the principle of equal saturation; to achieve the purpose of reducing the total delay of the intersection and improving the traffic capacity.

Description

Translated fromChinese

基于可变导向车道的信号配时优化方法Signal Timing Optimization Method Based on Variable Steering Lane

技术领域technical field

本发明属于道路交通控制领域，具体涉及在可变导向车道功能属性发生变化后，依据不同的道路饱和度确定信号配时的方法。The invention belongs to the field of road traffic control, and in particular relates to a method for determining signal timing according to different road saturations after the functional attribute of a variable guiding lane changes.

背景技术Background technique

随着社会经济的发展，汽车保有量的急剧增加，许多大中城市的交通拥堵现象也趋严重。城市交叉口是城市道路网中道路通行能力的“隘路”，是交通秩序混乱和交通事故的多发点。解决城市交通拥堵问题的关键之一是要提高城市交叉口的通行效率，其车道功能划分与信号配时设计是否合理直接影响到整个城市交通网络的运行状态。With the development of social economy and the rapid increase of car ownership, traffic congestion in many large and medium-sized cities is also becoming more and more serious. Urban intersections are the "narrow roads" of road capacity in the urban road network, and are frequent points of traffic disorder and traffic accidents. One of the keys to solving the problem of urban traffic congestion is to improve the traffic efficiency of urban intersections. Whether the lane function division and signal timing design are reasonable will directly affect the operation status of the entire urban traffic network.

可变车道管理技术就是一种动态的交通管理与控制方法，根据交通需求的变化，对路段车道或交叉口车道功能进行动态调整，以适应交通流量的变化。目前可变导向车道的实施在部分城市已经获得了较好的效果。但在可变导向车道转向功能发生变化后，原有的信号配时会存在一定的缺陷，考虑如何设置合理的信号配时方案，才能更好地提高可变导向车道的效率。Variable lane management technology is a dynamic traffic management and control method. According to the change of traffic demand, the function of lane or intersection lane is dynamically adjusted to adapt to the change of traffic flow. At present, the implementation of variable guiding lanes has achieved good results in some cities. However, after the steering function of the variable steering lane changes, the original signal timing will have certain defects. Only by considering how to set up a reasonable signal timing scheme can the efficiency of the variable steering lane be better improved.

同时，针对不同的交通流状况，信号控制策略也会有所差异，特别是饱和交通与低饱和交通存在着显著的不同。现有研究虽然对低流量和高流量下的信号控制进行分别讨论，但均以韦伯斯特法进行信号调整，忽略了韦伯斯特法在应对饱和交通时的缺陷。At the same time, for different traffic flow conditions, signal control strategies will also be different, especially the saturated traffic and low saturated traffic are significantly different. Although the existing studies discuss the signal control under low flow and high flow respectively, they all use the Webster method to adjust the signal, ignoring the defects of the Webster method when dealing with saturated traffic.

因此本发明在可变导向车道功能属性发生变化的基础上，针对不同条件下的优化目标以及不同的饱和度提出信号配置优化方案。Therefore, on the basis of changes in the functional attributes of the variable guiding lane, the present invention proposes a signal configuration optimization scheme for optimization objectives under different conditions and different saturations.

发明内容Contents of the invention

本发明的目的是提出一种基于可变导向车道的信号配时优化方法，在可变导向车道的基础上，协同信号配时的控制，使进口道饱和度控制在合理范围，减少交叉口延误，提高通行能力。The purpose of the present invention is to propose a signal timing optimization method based on variable guiding lanes, on the basis of variable guiding lanes, coordinate the control of signal timing, control the saturation of the entrance road within a reasonable range, and reduce intersection delays , improve traffic capacity.

本发明采用的技术方案为：基于可变导向车道的信号配时优化方法，具体包括：The technical solution adopted in the present invention is: a signal timing optimization method based on variable guiding lanes, specifically including:

1)检测器的布设；1) Layout of detectors;

将线圈检测器布设在距离进口道上游展宽段尾部，数量为进口直行车道、左转车道、可变导向车道上的线圈检测器的总和，用于检测各车道通过车辆数数据，由此获得进口道各转向流量交通参数；The coil detectors are arranged at the end of the widening section upstream of the entrance road, and the number is the sum of the coil detectors on the straight lane, left-turn lane and variable steering lane of the entrance, which is used to detect the number of passing vehicles in each lane, thus obtaining the entrance The traffic parameters of each turning flow of the road;

2)计算各转向饱和度：

其中q_i—i转向车流的单车道车流量，当量交通量/小时；CAP_i—i转向车流的通过能力，当量交通量/小时；2) Calculate each steering saturation:

Among them, q_i —the single-lane traffic volume of i-turned traffic flow, equivalent traffic volume/hour; CAP_i —i-turned traffic flow capacity, equivalent traffic volume/hour;

3）判断各转向的饱和度：若流量较低，非饱和状态下，改变可变导向车道转向功能后，各转向饱和度x_i≤x_o，其中x_o为临界饱和度时，信号配时转步骤4）；随着进口道流量的增加，特别表现在某一转向相位x_i＞x_o时，信号配时的调整转步骤5）；当进口道趋于拥堵，目标进口道的各转向流量比均明显大于对向进口道各转向流量比时，以常规四相位配时方案为基础，配时优化转步骤6）。3) Judging the saturation of each steering: If the flow rate is low and in the unsaturated state, after changing the steering function of the variable steering lane, the saturation of each steering x_i ≤ x_o , where x_o is the critical saturation, the signal timing Go to step 4); with the increase of inlet traffic, especially when a certain steering phase x_i > x_o , the adjustment of signal timing goes to step 5); when the inlet tends to be congested, each steering direction of the target inlet When the flow ratios are all significantly greater than the flow ratios of the opposite inlets, turn to step 6 for timing optimization based on the conventional four-phase timing scheme.

4）对于各转向饱和度x_i≤x_o其中x_o为临界饱和度，根据流量变化调整信号配时：4) For each steering saturation x_i ≤ x_o where x_o is the critical saturation, adjust the signal timing according to the flow change:

4.1）确定相位流量比变化值4.1) Determine the change value of phase flow ratio

假设原有左转车道数为a条，直行车道数为b条，考虑可变车道功能发生变化后，左转车道数变为a'条，直行车道数变为b'；则各相位流量比变为：Assuming that the original number of left-turning lanes is a, and the number of straight-going lanes is b, after considering the change of the variable lane function, the number of left-turning lanes becomes a', and the number of straight-going lanes becomes b'; then the flow ratio of each phase becomes:

左转相位流量比变为：The left turn phase flow ratio becomes:

${y the y}_{L L}^{' '} = = \frac{a a}{{a a}^{' '}} {y the y}_{L L} - - - - - - ((11))$

式中：y_L——左转相位原来的流量比；In the formula: y_L ——the original flow ratio of the left-turn phase;

y_L'——可变导向车道功能变换后左转相位的流量比；y_L '——the flow ratio of the left turn phase after the function change of the variable guiding lane;

直行相位相应流量比变为：The corresponding flow ratio of the straight forward phase becomes:

${y the y}_{T T}^{' '} = = \frac{b b}{{b b}^{' '}} {y the y}_{T T} - - - - - - ((22))$

式中：y_T——直行相位原来的流量比；In the formula: y_T —— original flow ratio of the straight-ahead phase;

y_T'——可变导向车道功能变换后直行相位的流量比；y_T '——the flow ratio of the straight-going phase after the function change of the variable guide lane;

进口道总交通流量比变为：The total traffic flow ratio of the entrance road becomes:

${Y Y}^{' '} = = Y Y + + \frac{{a a}^{' '} - - a a}{{a a}^{' '}} {y the y}_{L L} + + \frac{{b b}^{' '} - - b b}{{b b}^{' '}} {y the y}_{T T} - - - - - - ((33))$

4.2）确定信号周期和有效绿灯时间4.2) Determine the signal period and effective green light time

根据Webster最佳周期时长公式，信号周期应当变为：According to Webster's formula for optimal period duration, the signal period should become:

$C^{'} = \frac{1.5 L + 5}{1 - Y^{'}},$ 其中L为损失时间，（4） $C^{'} = \frac{1.5 L + 5}{1 - Y^{'}},$ where L is the lost time, (4)

可变导向车道功能变换后，左转相位有效绿灯时间变为：After the function of the variable guiding lane is changed, the effective green light time of the left turn phase becomes:

${g g}_{L L}^{' '} = = (({C C}^{' '} - - L L)) \frac{{y the y}_{L L}^{' '}}{{Y Y}^{' '}} - - - - - - ((55))$

可变导向车道功能变换后，直行相位有效绿灯时间变为：After the function of the variable guiding lane is changed, the effective green light time of the straight-going phase becomes:

${g g}_{T T}^{' '} = = (({C C}^{' '} - - L L)) \frac{{y the y}_{T T}^{' '}}{{Y Y}^{' '}} - - - - - - ((66))$

5）当可变导向车道功能属性发生变化后，表现在某一转向相位过饱和，即x_i＞x_o时，其信号配时优化方法为：5) When the functional attributes of the variable steering lane change, it appears that a certain steering phase is oversaturated, that is, when x_i > x_o , the signal timing optimization method is as follows:

5.1）计算初始配时方案5.1) Calculate the initial timing scheme

以满足车辆延误最小为目标，以经典Webster方法得到初始配时方案，信号周期和有效绿灯时间如式（4）、（5）、（6）所示；To meet the minimum vehicle delay as the goal, the initial timing scheme is obtained by the classic Webster method, and the signal period and effective green light time are shown in equations (4), (5), and (6);

5.2）计算车道车均延误；5.2) Calculate the average delay of vehicles in the lane;

采用Akcelik延误计算公式：Using the Akcelik delay calculation formula:

$d d = = \frac{C C {((11 - - g g / / C C))}^{22}}{22 ((11 - - q q / / S S))} + + \frac{{Q Q}_{00} x x}{q q} - - - - - - ((77))$

式中：C——信号周期；g——有效绿灯时间；q——车流量；Q₀——平均饱和排队车辆数的过渡函数，其计算公式为：In the formula: C—signal period; g—effective green light time; q—traffic flow; Q₀ —transition function of the average number of saturated queuing vehicles, and its calculation formula is:

${Q Q}_{00} = = \{\begin{matrix} \frac{1.5 1.5 ((x x - - {x x}_{11}))}{11 - - x x} & x x > > {x x}_{11} \\ 00 & x x \leq \leq {x x}_{11} \end{matrix} - - - - - - ((88))$

式中：x₁——饱和度阈值，对应车道的达到饱和流量时的饱和度；当饱和度大于x₀时，出现平均饱和排队车辆数，x₁计算公式如下：In the formula: x₁ ——saturation threshold, which corresponds to the saturation of the lane when the traffic reaches saturation; when the saturation is greater than x₀ , the average number of saturated queuing vehicles appears, and the calculation formula of x₁ is as follows:

${x x}_{11} = = 0.67 0.67 + + \frac{{g g}_{e e}}{600600} - - - - - - ((99))$

5.3）采用爬山法优化周期时长和相位绿信比；5.3) Use the hill-climbing method to optimize the cycle duration and phase green signal ratio;

a.首先对周期进行调整，把周期向正方向以一定步长进行一次调整后，计算此时的延误d；a. Firstly adjust the cycle, adjust the cycle to the positive direction with a certain step length, and calculate the delay d at this time;

b.不改变周期，定步长调整绿信比，分为正向与反向调整；当向正向调整计算得到每辆车的平均延误d’较延误d减少时，说明该方向调整绿信比有效，继续调整直至最小延误值；若绿信比调整中计算值较延误值d大，说明绿信比调整方向不正确，继续反向调整，直至获得最小延误；调整过程中要对每个方案的主要进口道饱和度进行检验，当饱和度<0.9，该方案有效；b. Without changing the cycle, adjust the green signal ratio with a fixed step length, which is divided into positive and negative adjustments; when the average delay d' of each vehicle is reduced by the calculation of the positive adjustment, it means that the green signal is adjusted in this direction If the ratio is valid, continue to adjust until the minimum delay value; if the calculated value in the adjustment of the green letter ratio is greater than the delay value d, it means that the adjustment direction of the green letter ratio is incorrect, and continue to adjust in the opposite direction until the minimum delay value is obtained; during the adjustment process, each The saturation of the main inlet of the scheme shall be tested, and when the saturation is <0.9, the scheme is valid;

c.该周期获得的最小延误值与调整周期前的延误值进行对比；若延误值降低，说明周期调整方向正确，循环上述步骤2.1）、2.2）继续调整；若延误值未降低，则减小一定步长周期时间进行调整，绿信比的调整同步骤2.2）；c. Compare the minimum delay value obtained in this cycle with the delay value before the adjustment cycle; if the delay value decreases, it means that the cycle adjustment direction is correct, and repeat the above steps 2.1) and 2.2) to continue the adjustment; if the delay value does not decrease, then decrease Adjust the cycle time with a certain step length, and the adjustment of the green letter ratio is the same as step 2.2);

d.当无论周期增加或减少、绿信比如何调整，延误值都不再变小时，优化完毕；d. When the delay value no longer decreases no matter how the period increases or decreases, or how the green letter ratio is adjusted, the optimization is completed;

5.4）建立优化模型；5.4) Establish an optimization model;

以交叉口目标进口道总延误作为目标函数，总延误为目标进口道每车道的车均延误与该车道到达交通量的乘积之和：Taking the total delay of the target entrance at the intersection as the objective function, the total delay is the sum of the product of the average vehicle delay of each lane of the target entrance and the arrival traffic volume of the lane:

$min min {D D.}^{' '} = = \underset{i i}{Σ Σ} {d d}_{i i} {q q}_{i i} - - - - - - ((1010))$

$s the s . . t t . . \{\begin{matrix} 2020 K K \leq \leq C C \leq \leq 6060 K K \\ {Σ Σ}_{k k = = 11}^{K K} {g g}_{ek ek} + + L L = = C C \end{matrix}$

式中：D'——目标进口道总延误；In the formula: D' - the total delay of the target entrance;

d_i——第i车道的车均延误，单位为秒；d_i ——the average delay of vehicles in the i-th lane, in seconds;

q_i——第i车道的车流量，单位为当量交通量/小时；q_i ——the traffic volume of the i-th lane, the unit is equivalent traffic volume/hour;

约束条件包括：①周期时长的约束，即大于各相位最小绿灯的时长之和，小于各相位最大绿灯时长之和，取最小绿灯时长为20s，最大绿灯时长为60s，因此给出公式：20K≤C≤60K，其中K为该交叉口相位数；②各相位有效绿灯时长之和与损失时间相加应等于周期时长，即：

Constraints include: ① The constraint on cycle duration, that is, greater than the sum of the minimum green light durations of each phase and less than the sum of the maximum green light durations of each phase, the minimum green light duration is 20s, and the maximum green light duration is 60s, so the formula is given: 20K≤ C≤60K, where K is the number of phases at the intersection; ②The sum of the effective green light duration of each phase and the lost time should be equal to the cycle duration, namely:

6）当改变可变导向车道功能属性后，若目标进口道的各转向流量比均明显大于对向进口道各转向流量比，则以常规四相位配时方案为基础，确定信号配时方法为：6) After changing the functional attributes of the variable guiding lane, if the turning flow ratios of the target entrance lanes are significantly greater than the turning flow ratios of the opposite entrance lanes, then based on the conventional four-phase timing scheme, the signal timing method is determined as :

6.1）划分相位组；6.1) Divide phase groups;

常规四相位基础上增加一个相位：目标进口道的直行和左转，这里考虑目标进口道为由南向北方向，相位增加到5个，并重新划分为3个组合相位组：One phase is added on the basis of the conventional four phases: straight-going and left-turning of the target entrance. Here, considering the direction of the target entrance from south to north, the phases are increased to 5 and re-divided into 3 combined phase groups:

组合相位组1：东西向直行ET、WT；Combined phase group 1: East-West straight ET, WT;

组合相位组2：东西向左转EL、WL；Combination phase group 2: Turn left from east to west to EL, WL;

组合相位组3：南北向直行NT、ST；南向北直行ST和左转SL；南北向左转NL、SL；Combined phase group 3: go straight to NT and ST in north-south direction; go straight to ST and turn left in south-north direction; turn left in NL and SL in north-south direction;

6.2）寻找各组合相位组的关键相位链；6.2) Find the key phase chains of each combined phase group;

相位组1中相位链为ET或WT，相位组2中为EL或WL，相位组3中为NT和SL，或NL和ST，各相位组关键相位链的流量比：The phase chain in phase group 1 is ET or WT, the phase chain inphase group 2 is EL or WL, and the phase chain inphase group 3 is NT and SL, or NL and ST. The flow rate ratio of the key phase chains in each phase group is:

y₁＝max(y_ET,y_WT) （11）y₁ =max(y_ET ,y_WT ) (11)

y₂＝max(y_EL,y_WL) （12）y₂ =max(y_EL ,y_WL ) (12)

y₃＝max(y_NT+y_SL,y_NL+y_ST) （13）y₃ ＝max(y_NT +y_SL ,y_NL +y_ST ) (13)

6.3）根据韦伯斯特公式计算最佳周期时长；6.3) Calculate the optimal cycle time according to Webster's formula;

进口道总交通流量比： $Y = Σ_{i = 1}^{3} y_{i} - - - (14)$ The total traffic flow ratio of the entrance road: $Y = Σ_{i = 1}^{3} {the y}_{i} - - - (14)$

信号周期： $C = \frac{1.5 L + 5}{1 - Y} - - - (15)$ Signal period: $C = \frac{1.5 L + 5}{1 - Y} - - - (15)$

6.4）按等饱和度原则分配绿灯时间；6.4) Allocate green light time according to the principle of equal saturation;

设有效绿灯时间为G，各相位组绿灯时间为g_i，则：Assuming that the effective green light time is G, and the green light time of each phase group is g_i , then:

${g g}_{i i} = = G G \frac{{y the y}_{i i}}{Y Y} = = ((C C - - L L)) \frac{{y the y}_{i i}}{Y Y},, i i = = 1,2,3 1,2,3 - - - - - - ((1616))$

其中相位组3中包含3个阶段，需要对各阶段的时间继续进分配，假设y_NT+y_SL＞y_NL+y_ST，则NT和SL为关键组合相位链，其中y_SL＞y_NL，且y_ST＞y_NT，设相位组3中各转向车流有效绿灯时间为g_3j，其中j＝1,2,3,4，各转向的有效绿灯时间分别为：Among them,phase group 3 contains 3 stages, and the time of each stage needs to be further allocated. Assuming y_NT +y_SL >y_NL +y_ST , then NT and SL are the key combined phase chains, where y_SL >y_NL , And y_ST >y_NT , assuming that the effective green light time of each turn inphase group 3 is g_3j , where j=1, 2, 3, 4, the effective green light time of each turn is:

北向南直行： $g_{31} = \frac{y_{NT}}{y_{NT} + y_{SL}} g_{3} - - - (17)$ Going straight north to south: $g_{31} = \frac{{the y}_{NT}}{{the y}_{NT} + {the y}_{SL}} g_{3} - - - (17)$

南向北直行： $g_{32} = \frac{y_{ST}}{y_{NT} + y_{SL}} g_{3} - - - (18)$ Going straight from south to north: $g_{32} = \frac{{the y}_{ST}}{{the y}_{NT} + {the y}_{SL}} g_{3} - - - (18)$

南向北左转： $g_{33} = \frac{y_{SL}}{y_{NT} + y_{SL}} g_{3} - - - (19)$ Turn left from south to north: $g_{33} = \frac{{the y}_{SL}}{{the y}_{NT} + {the y}_{SL}} g_{3} - - - (19)$

北向南左转： $g_{34} = \frac{y_{NT} + y_{SL} - y_{ST}}{y_{NT} + y_{SL}} g_{3} - - - (20) .$ Turn left from north to south: $g_{34} = \frac{{the y}_{NT} + {the y}_{SL} - {the y}_{ST}}{{the y}_{NT} + {the y}_{SL}} g_{3} - - - (20) .$

1、本发明提出了基于可变导向车道的信号配时优化方法，针对不同交通状态下，提出了不同的控制目标和策略，分别在非饱和状态和饱和状态时，确定了可变导向车道功能变换后相应的信号配时方案。1. The present invention proposes a signal timing optimization method based on variable guiding lanes, and proposes different control objectives and strategies for different traffic conditions, and determines the function of variable guiding lanes in unsaturated and saturated states respectively. The corresponding signal timing scheme after transformation.

2、针对进口道时段性、方向性转向不均衡交通的特征，通过车道功能与信号配时的协同控制，使进口道饱和度控制在合理范围，进而达到减小交叉口总延误、提高通行能力的效果。2. Aiming at the characteristics of time-period and directional steering unbalanced traffic at the entrance, through the coordinated control of lane function and signal timing, the saturation of the entrance can be controlled within a reasonable range, thereby reducing the total delay at the intersection and improving the traffic capacity Effect.

附图说明Description of drawings

图1为不同交通状态下信号配时逻辑流程图；Figure 1 is a logic flow chart of signal timing under different traffic conditions;

图2为常规四相位信号控制交叉口示意图；Figure 2 is a schematic diagram of a conventional four-phase signal control intersection;

图3为常规四相位信号配时示意图；FIG. 3 is a schematic diagram of conventional four-phase signal timing;

图4为爬山法目标相位信号配时优化优化流程图；Fig. 4 is the optimization flow chart of hill climbing method target phase signal timing optimization;

图5为重组合的相位组合方案以及信号配时方案示意图。FIG. 5 is a schematic diagram of a recombination phase combination scheme and a signal timing scheme.

具体实施方式Detailed ways

下面结合附图和具体实施方式对本发明做进一步说明。The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

针对存在可变导向车道的交叉口，当可变导向车道满足转换条件，考虑车道由直行功能转变成左转，根据目标车道流量的变化，计算饱和度，判断不同车道转向饱和度是否达到饱和度阀值，确定不同状态下的信号配时优化方案，如图1所示。For intersections with variable directional lanes, when the variable directional lanes meet the transition conditions, consider the lane from going straight to turning left, and calculate the saturation according to the change in the flow of the target lane, and judge whether the steering saturation of different lanes reaches saturation Threshold, determine the signal timing optimization scheme in different states, as shown in Figure 1.

以常规四相位十字交叉口为例，其信号配时如图2所示：Taking the conventional four-phase intersection as an example, its signal timing is shown in Figure 2:

步骤一：将检测器布设在距离进口道上游展宽段尾部，如图3所示；Step 1: Arrange the detector at the end of the widening section upstream of the entrance road, as shown in Figure 3;

步骤二：计算各转向饱和度：

其中q_i—i转向车流的单车道车流量，当量交通量/小时；CAP_i—i转向车流的通过能力，当量交通量/小时；Step 2: Calculate the saturation of each steering:

步骤三：假设原有左转车道数为a条，直行车道数为b条，考虑可变车道功能发生变化后，左转车道数变为a'条，直行车道数变为b'；当车流量较低时，各转向饱和度x_i≤x_o，其中x_o为临界饱和度，根据流量变化调整相位配时：Step 3: Assume that the original number of left-turning lanes is a, and the number of straight-going lanes is b. After considering the change of the variable lane function, the number of left-turning lanes becomes a', and the number of straight-going lanes becomes b'; When the flow is low, each steering saturation x_i ≤ x_o , where x_o is the critical saturation, adjust the phase timing according to the flow change:

左转相位流量比变为：

其中yL——左转相位原来的流量比，y_L'——可变导向车道功能变换后左转相位的流量比；The left turn phase flow ratio becomes:

Among them, yL - the original flow ratio of the left-turn phase, y_L ' - the flow ratio of the left-turn phase after the function transformation of the variable guiding lane;

直行相位流量比变为：

其中y_T——直行相位原来的流量比，y_T'——可变导向车道功能变换后直行相位的流量比；The straight-going phase flow ratio becomes:

Among them, y_T - the original flow ratio of the straight-going phase, y_T ' - the flow ratio of the straight-going phase after the function transformation of the variable guiding lane;

进口道总交通流量比变为： $Y^{'} = Y + \frac{a^{'} - a}{a^{'}} y_{L} + \frac{b^{'} - b}{b^{'}} y_{T}$ The total traffic flow ratio of the entrance road becomes: $Y^{'} = Y + \frac{a^{'} - a}{a^{'}} {the y}_{L} + \frac{b^{'} - b}{b^{'}} {the y}_{T}$

信号周期应当变为：

其中L为损失时间The signal period should become:

where L is the lost time

可变导向车道功能变换后，直行相位有效绿灯时间变为：

After the function of the variable guiding lane is changed, the effective green light time of the straight-going phase becomes:

步骤四：随着车流量的增加，转变可变导向车道功能属性后，当某一转向相位x_i＞x_o时，其信号配时优化方法为：Step 4: With the increase of traffic flow, after changing the functional attributes of the variable steering lane, when a certain steering phase x_i > x_o , the signal timing optimization method is as follows:

1）计算初始配时方案；1) Calculate the initial timing plan;

以满足车辆延误最小为目标，以经典Webster方法得到最优配时方案，信号周期和有效绿灯时间式，如步骤二所示；To meet the minimum vehicle delay as the goal, the optimal timing scheme, signal period and effective green light time formula are obtained by using the classic Webster method, as shown instep 2;

2）计算车道车均延误；2) Calculate the average delay of vehicles in the lane;

采用Akcelik延误计算公式：其中C——信号周期；g——有效绿灯时间；q——车流量；Q₀——平均饱和排队车辆数的过渡函数，其计算公式为： $Q_{0} = \{\begin{matrix} \frac{1.5 (x - x_{1})}{1 - x} & x > x_{1} \\ 0 & x \leq x_{1} \end{matrix},$ x₁为饱和度阈值，对应车道的达到饱和流量时的饱和度；当饱和度大于x₁时，出现平均饱和排队车辆数，Using the Akcelik delay calculation formula: Among them, C—signal period; g—effective green light time; q—traffic flow; Q₀ —transition function of the average number of saturated queuing vehicles, and its calculation formula is: $Q_{0} = \{\begin{matrix} \frac{1.5 (x - x_{1})}{1 - x} & x > x_{1} \\ 0 & x \leq x_{1} \end{matrix},$ x₁ is the saturation threshold, which corresponds to the saturation of the lane when the traffic reaches saturation; when the saturation is greater than x₁ , the average number of saturated queuing vehicles appears,

3）针对目标进口道的左转和直行相位，采用爬山法优化周期时长和相位绿信比，如图4所示，其中相位A为左转相位，相位B为直行相位；3) For the left-turn and straight-going phases of the target entrance, the hill-climbing method is used to optimize the cycle duration and phase green signal ratio, as shown in Figure 4, where phase A is the left-turn phase and phase B is the straight-going phase;

4）建立优化模型4) Build an optimization model

$min min {D D.}^{' '} = = \underset{i i}{Σ Σ} {d d}_{i i} {q q}_{i i}$

其中，D'——目标进口道总延误，d_i——第i车道的车均延误,单位为秒，q_i——第i车道的车流量，单位为当量交通量/小时；Among them, D'—the total delay of the target entrance, d_i —the average delay of vehicles in the i-th lane, the unit is second, q_i ——the traffic flow of the i-th lane, the unit is equivalent traffic volume/hour;

步骤五：随着车流量的继续增加，变换可变导向车道后，若目标进口道的各转向流量比均明显大于对向进口道各转向流量比，则信号配时方案：Step 5: As the traffic volume continues to increase, after changing the variable directional lane, if the turning flow ratios of the target entrance lane are significantly greater than the turning flow ratios of the opposite entrance lane, the signal timing scheme is as follows:

1）由于在常规四相位基础上增加一个相位4，相位增加到5个，将相位3、4和5合并为相位组3，划分3个组合相位组；其相位组合与信号配时方案如图5所示；1) Since a phase 4 is added on the basis of the conventional four phases, the number of phases is increased to 5, phases 3, 4 and 5 are combined intophase group 3, and three combined phase groups are divided; the phase combination and signal timing scheme are shown in the figure 5 shown;

2）寻找各组合相位组的关键相位链；2) Find the key phase chains of each combined phase group;

y₁＝max(y_ET,y_WT)y₁ =max(y_ET ,y_WT )

y₂＝max(y_EL,y_WL)y₂ =max(y_EL ,y_WL )

y₃＝max(y_NT+y_SL,y_NL+y_ST)y₃ =max(y_NT +y_SL ,y_NL +y_ST )

3）根据韦伯斯特公式计算最佳周期时长；3) Calculate the optimal cycle time according to Webster's formula;

进口道总交通流量比：

The total traffic flow ratio of the entrance road:

信号周期：

Signal period:

4）按等饱和度原则分配绿灯时间；4) Allocate green light time according to the principle of equal saturation;

${g g}_{i i} = = G G \frac{{y the y}_{i i}}{Y Y} = = ((C C - - L L)) \frac{{y the y}_{i i}}{Y Y},, i i = = 1,2,3 1,2,3$

北向南直行： $g_{31} = \frac{y_{NT}}{y_{NT} + y_{SL}} g_{3}$ Going straight north to south: $g_{31} = \frac{{the y}_{NT}}{{the y}_{NT} + {they}_{SL}} g_{3}$

南向北直行： $g_{32} = \frac{y_{ST}}{y_{NT} + y_{SL}} g_{3}$ Going straight from south to north: $g_{32} = \frac{{the y}_{ST}}{{the y}_{NT} + {they}_{SL}} g_{3}$

南向北左转： $g_{33} = \frac{y_{SL}}{y_{NT} + y_{SL}} g_{3}$ Turn left from south to north: $g_{33} = \frac{{the y}_{SL}}{{the y}_{NT} + {they}_{SL}} g_{3}$

北向南左转： $g_{34} = \frac{y_{NT} + y_{SL} - y_{ST}}{y_{NT} + y_{SL}} g_{3}$ Turn left from north to south: $g_{34} = \frac{{the y}_{NT} + {the y}_{SL} - {the y}_{ST}}{{the y}_{NT} + {they}_{SL}} g_{3}$

下面结合具体仿真实例做具体说明：The following is a specific description combined with a specific simulation example:

以典型十字交叉口为仿真背景，如图2所示。Take a typical intersection as the simulation background, as shown in Figure 2.

该交叉口东西向进口道均为3车道，均有一条左转、直行、右转车道；南北向进口道为有展宽式进口道，进口道为5车道。北进口道有2条单独的左转车道、2条直行车道以及1条右转车道，南进口道为设有可变导向车道的目标进口道，其中第二条车道设为直行/左转可变导向车道，其余为1条左转车道、2条直行车道和1条右转车道。The east-west entrance lanes of the intersection are all 3-lane, with a left-turn, straight-going, and right-turn lanes; the north-south entrance lanes have widened entrance lanes, and the entrance lanes have 5 lanes. The north entrance has 2 separate left-turn lanes, 2 through lanes and 1 right-turn lane. The south entrance is a target entrance with variable directional lanes, and the second lane is set to go straight/left turn. The remaining lanes are 1 left turn lane, 2 through lanes and 1 right turn lane.

目标进口道（南进口道）展宽段长度为60m，渐变段约35m。The length of the widened section of the target entrance road (south entrance road) is 60m, and the transition section is about 35m.

1、初始配时方案1. Initial timing plan

交叉口各进口道的交通流量初始数据如表1所示：The initial traffic flow data of each entrance lane at the intersection is shown in Table 1:

表1交叉口初始流量Table 1 Initial flow at intersection

该进口道原信号配时方案为：周期为90s，东西向直行相位20s，东西向左转相位15s，南北向直行相位22s，南北向左转相位21s。保持东西向各转向车流量不变，目标进口道各转向车流量随时间变换。The original signal timing scheme of the entrance channel is as follows: the period is 90s, the phase of going straight from east to west is 20s, the phase of turning left from east to west is 15s, the phase of going straight from north to south is 22s, and the phase of turning left from north to south is 21s. Keep the east-west turning traffic flow constant, and the target entrance road turning traffic flow changes with time.

初始可变导向车道转向功能为直行，南进口道（不考虑右转车道）为1条左转、3条直行车道。南进口道左转和直行方向在不同时段流量如表2所示The steering function of the initial variable steering lane is going straight, and the south entrance road (not considering the right-turn lane) has 1 left-turn and 3 straight lanes. The flow of left-turn and straight-going direction of the south entrance road in different time periods is shown in Table 2

表2目标进口道不同时段各转向流量Table 2 Turning flow of target inlet channel in different time periods

时段（s）time period (s)0-12000-12001200-24001200-24002400-36002400-36003600-48003600-48004800-60004800-6000左转流量（pcu/h）Left turn flow (pcu/h)250250300300350350450450500500直行流量（pcu/h）Straight flow (pcu/h)830830880880880880880880880880

2、饱和度2. Saturation

利用仿真得到的各转向排队长度与连续3周期通过车辆数计算饱和度，如表3所示：The saturation is calculated using the queuing length of each turn and the number of passing vehicles in three consecutive cycles obtained from the simulation, as shown in Table 3:

表3各周期各转向最大排队长度仿真统计表Table 3 Simulation statistics of the maximum queue length for each direction in each cycle

3、不饱和状态下信号配时方案3. Signal timing scheme in unsaturated state

可变导向车道由直行车道变为左转车道，在不改变周期情况下，对交叉口进行信号配时优化，给出的最优配时方案为：周期为90s，东西向直行相位20s，东西向左转相位15s，南北向直行相位26s，南北向左转相位17s。The variable directional lane changes from a straight lane to a left-turn lane. Without changing the period, the signal timing optimization is carried out at the intersection. The optimal timing scheme given is: the period is 90s, the east-west straight phase is 20s, and the east-west The phase of turning to the left is 15s, the phase of going straight from north to south is 26s, and the phase of turning to the left from north to south is 17s.

利用仿真，计算车辆平均延误、停车次数，对该方案与初始信号配时方案进行对比，如表4所示：Using simulation, calculate the average delay and parking times of vehicles, and compare this scheme with the initial signal timing scheme, as shown in Table 4:

表4各项指标对比表Table 4 Comparison table of various indicators

4、单方向过饱和状态下信号配时方案4. Signal timing scheme under unidirectional oversaturation state

以时段4800s～6000s为例，即左转流量为500pcu/h，直行流量为880pcu/h时，此时，若不改变信号配时，则计算得到左转车流饱和度为0.62，直行车流饱和度为0.96>0.9，直行方向过饱和，采用单方向过饱和优化方法对交叉口进行信号配时优化。Take the time period 4800s～6000s as an example, that is, when the left-turn traffic flow is 500pcu/h and the straight-going traffic flow is 880pcu/h, at this time, if the signal timing is not changed, the calculated left-turn traffic flow saturation is 0.62, and the straight-going traffic flow saturation is 0.62. is 0.96>0.9, the straight direction is oversaturated, and the signal timing optimization of the intersection is carried out by using the unidirectional oversaturation optimization method.

给出信号配时优化方案为：周期为85s，东西向直行相位19s，东西向左转相位14s，南北向直行相位25s，南北向左转相位15s。The signal timing optimization scheme is given as follows: the cycle is 85s, the east-west straight phase is 19s, the east-west leftward phase is 14s, the north-south straight phase is 25s, and the north-south leftward phase is 15s.

利用仿真，计算车辆平均延误、停车次数，对该方案与初始信号配时方案进行对比，如表5所示：Using simulation, calculate the average delay and parking times of vehicles, and compare this scheme with the initial signal timing scheme, as shown in Table 5:

表5各项指标对比表Table 5 Comparison table of various indicators

5、进口道各转向均饱和状态下的信号配时优化方案5. The signal timing optimization scheme under the condition that all steering directions of the entrance road are saturated

若左转方向和直行方向车流进一步增加，左转流量达到650pcu/h，直行流量达到1030pcu/h时，计算得到南进口道的各转向的流量比均明显大于北进口道对应转向流量比。If the traffic flow in the left-turning direction and the straight-going direction further increases, and the left-turning traffic reaches 650pcu/h, and the straight-going traffic reaches 1030pcu/h, the calculated flow ratios of each turn at the south entrance are significantly greater than the corresponding turn flow ratios at the north entrance.

根据提出的信号配时方法，对相位进行调整，在传统四相位基础上增加南进口道左转直行相位。提出配时方案为：周期111s，东西向直行相位24s，东西向左转相位18s，北向南直行相位29s，南向北直行相位38s，南向北左转相位28s，北向南左转相位19s。According to the proposed signal timing method, the phase is adjusted, and the left-turn and straight-going phase of the south entrance is added on the basis of the traditional four-phase. The proposed timing scheme is as follows: cycle 111s, east-west straight phase 24s, east-west left-turn phase 18s, north-south straight phase 29s, south-north straight phase 38s, south-north left-turn phase 28s, north-south left-turn phase 19s.

通过仿真，从车均延误、最大排队长度对该方案与传统Webster法给出配时方案进行对比，如表6所示：Through simulation, this scheme is compared with the timing scheme given by the traditional Webster method in terms of average vehicle delay and maximum queuing length, as shown in Table 6:

表6各项指标对比表Table 6 Comparison table of various indicators

应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。It should be pointed out that those skilled in the art can make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. the signal timing dial optimization method based on variable guided vehicle road, is characterized in that, comprises following steps:

1) laying of detecting device;

Coil checker is laid in apart from entrance driveway upstream broadening segment trailer, quantity is the summation of the coil checker in import Through Lane, left turn lane, variable guided vehicle road, for detection of each track, by vehicle number data, obtain thus each steering flow traffic parameter of entrance driveway;

2) calculate and respectively turn to saturation degree:

q wherein_i-i turns to the bicycle road vehicle flowrate of wagon flow, the equivalent volume of traffic/hour; CAP_i-i turns to the handling capacity of wagon flow, the equivalent volume of traffic/hour;

3) saturation degree that judgement respectively turns to: if flow is lower, in unsaturated state, change after variable guided vehicle road turning function, respectively turn to saturation degree x_i≤ x_otime, x wherein_ofor critical saturation, signal timing dial goes to step 4); Along with the increase of entrance driveway flow, show especially a certain phase place x that turns to_i> x_otime, the adjustment of signal timing dial goes to step 5); When entrance driveway is tending towards blocking up, each steering flow of target entrance driveway than be all obviously greater than each steering flow of subtend entrance driveway than time, take conventional four multiphase traffic time allocation schemes as basis, timing optimization goes to step 6);

4) for respectively turning to saturation degree x_i≤ x_o, x wherein_ofor critical saturation, according to fluctuations in discharge, adjust signal timing dial:

4.1) determine phase place throughput ratio changing value;

Suppose that original left turn lane number is a bar, Through Lane number is b bar, and after considering that changeable driveway function changes, left turn lane number becomes a' bar, and Through Lane number becomes b'; Each phase place throughput ratio becomes:

Left turn phase throughput ratio becomes:

{y_{L}}^{'} = \frac{a}{a^{'}} y_{L} - - - (1)

In formula: y_l---the throughput ratio that left turn phase is original;

Y_l'---the throughput ratio of left turn phase after variable guided vehicle road functional mapping;

Craspedodrome phase place corresponding discharge ratio becomes:

{y_{T}}^{'} = \frac{b}{b^{'}} y_{T} - - - (2)

In formula: y_t---the throughput ratio that craspedodrome phase place is original;

Y_t'---the throughput ratio of the phase place of keeping straight on after variable guided vehicle road functional mapping;

The total magnitude of traffic flow ratio of entrance driveway becomes:

Y^{'} = Y + \frac{a^{'} - a}{a^{'}} y_{L} + \frac{b^{'} - b}{b^{'}} y_{T} - - - (3)

4.2) determine signal period and effective green time;

According to Webster optimal period duration formula, the signal period should become:

C^{'} = \frac{1.5 L + 5}{1 - Y^{'}},

Wherein L is lost time, (4)

After variable guided vehicle road functional mapping, left turn phase effective green time becomes:

{g_{L}}^{'} = (C^{'} - L) \frac{{y_{L}}^{'}}{Y^{'}} - - - (5)

After variable guided vehicle road functional mapping, craspedodrome phase place effective green time becomes:

{g_{T}}^{'} = (C^{'} - L) \frac{{y_{T}}^{'}}{Y^{'}} - - - (6)

5), after variable guided vehicle road functional attributes changes, show a certain phase place supersaturation, the i.e. x of turning to_i> x_otime, its signal timing dial optimization method is:

5.1) calculate initial timing scheme

Take and meet vehicle to incur loss through delay minimum be target, with classical Webster method, obtain initial timing scheme, signal period and effective green time are suc as formula shown in (4), (5), (6);

5.2) calculating track car all incurs loss through delay;

Adopt Akcelik delay estimation formula:

d = \frac{C {(1 - g / C)}^{2}}{2 (1 - q / S)} + \frac{Q_{0} x}{q} - - - (7)

In formula: C---the signal period; G---effective green time; Q---vehicle flowrate; Q₀---the transition function of average saturated queuing vehicle number, its computing formula is:

Q_{0} = \{\begin{matrix} \frac{1.5 (x - x_{1})}{1 - x} & x > x_{1} \\ 0 & x \leq x_{1} \end{matrix} - - - (8)

In formula: x₁---saturation degree threshold value, the saturation degree reaching capacity during flow in corresponding track; When saturation degree is greater than x₀time, there is average saturated queuing vehicle number, x₁computing formula is as follows:

x_{1} = 0.67 + \frac{g_{e}}{600} - - - (9)

5.3) adopt climbing method optimization cycle duration and phase place split;

5.4) set up Optimized model;

Using crossing target entrance driveway total delay as objective function, and total delay is that the car in the every track of target entrance driveway is all incured loss through delay the sum of products that arrives the volume of traffic with this track:

\min D^{'} = \underset{i}{Σ} d_{i} q_{i} - - - (10)

s . t . \{\begin{matrix} 20 K \leq C \leq 60 K \\ Σ_{k = 1}^{K} g_{ek} + L = C \end{matrix}

In formula: D'---target entrance driveway total delay;

D_i---the car in i track is all incured loss through delay, and unit is second;

Q_i---the vehicle flowrate in i track, unit be the equivalent volume of traffic/hour;

Constraint condition comprises: the 1. constraint of cycle duration, be greater than the duration sum of the minimum green light of each phase place, and be less than the maximum long green light time sum of each phase place, getting minimum long green light time is 20s, maximum long green light time is 60s, therefore provides formula: 20K≤C≤60K, and wherein K is this crossing number of phases; 2. are added each phase place Effective Green Time duration sum and lost time and should equal cycle duration, that is:

6) after changing variable guided vehicle road functional attributes, if each steering flow of target entrance driveway is obviously greater than each steering flow ratio of subtend entrance driveway than all, take conventional four multiphase traffic time allocation schemes as basis, determine that signal timing dial method is:

6.1) division phase group;

In conventional four phase basis, increase a phase place: the craspedodrome of target entrance driveway and left-hand rotation, consider here target entrance driveway for by the south orientation north to, phase place is increased to 5, and is reclassified as 3 combinatorial phase groups:

Combinatorial phase group 1: East and West direction craspedodrome ET, WT;

Combinatorial phase group 2: East and West direction left-hand rotation EL, WL;

Combinatorial phase group 3: north-south craspedodrome NT, ST; South orientation north craspedodrome ST and left-hand rotation SL; North-south left-hand rotation NL, SL;

6.2) find the key signal phase chain of each combinatorial phase group;

In phase-group 1, phase place chain is ET or WT, is EL or WL in phase-group 2, is NT and SL in phase-group 3, or NL and ST, the throughput ratio of each phase-group key signal phase chain:

y₁＝max(y_ET,y_WT) （11）

y₂＝max(y_EL,y_WL) （12）

y₃＝max(y_NT+y_SL,y_NL+y_ST) （13）

6.3) according to Robert Webster formula, calculate optimal period duration;

The total magnitude of traffic flow ratio of entrance driveway:

Y = Σ_{i = 1}^{3} y_{i} - - - (14)

Signal period:

C = \frac{1.5 L + 5}{1 - Y} - - - (15)

6.4) press isosaturation principle and distribute green time;

If effective green time is G, each phase-group green time is g_i:

g_{i} = G \frac{y_{i}}{Y} = (C - L) \frac{y_{i}}{Y}, i = 1,2,3 - - - (16)

Wherein in phase-group 3, comprise 3 stages, need to continue, into distribution, to suppose y to the time in each stage_nT+ y_sL> y_nL+ y_sT, NT and SL are crucial combinatorial phase chain, wherein y_sL> y_nL, and y_sT> y_nT, establishing and respectively turning to wagon flow effective green time in phase-group 3 is g_3j, j=1 wherein, 2,3,4, the effective green time respectively turning to is respectively:

Keep straight in north orientation south:

g_{31} = \frac{y_{NT}}{y_{NT} + y_{SL}} g_{3} - - - (17)

Keep straight in south orientation north:

g_{32} = \frac{y_{ST}}{y_{NT} + y_{SL}} g_{3} - - - (18)

Turn left in south orientation north:

g_{33} = \frac{y_{SL}}{y_{NT} + y_{SL}} g_{3} - - - (19)

Turn left in north orientation south:

g_{34} = \frac{y_{NT} + y_{SL} - y_{ST}}{y_{NT} + y_{SL}} g_{3} - - - (20) .

2. the signal timing dial optimization method based on variable guided vehicle road according to claim 1, is characterized in that step 4.3) described climbing method is:

2.1) first the cycle is adjusted, after the cycle is once adjusted with a fixed step size to positive dirction, calculated delay d now;

2.2) do not change the cycle, fixed step size is adjusted split, is divided into forward and oppositely adjusts, and when calculating the mean delay d ' of each car to forward adjustment and incur loss through delay d and reduce, illustrates that this direction is adjusted split effective, continues to adjust until minimum delay value; If calculated value is large compared with delay value d in split adjustment, illustrate that split is adjusted poor direction true, continue oppositely to adjust, until acquisition minimum delay, in adjustment process, will test to the main body entrance road saturation degree of each scheme, as saturation degree <0.9, this scheme is effective;

2.3) the minimum delay value that obtains contrasts with the delay value before adjustment cycle this in cycle, if delay value reduces, the explanation cycle is adjusted in the right direction, circulation above-mentioned steps 2.1), 2.2) continue adjustment; If delay value does not reduce, reduce a fixed step size and adjust cycle length, the adjustment of split is with step 2.2);

2.4) when no matter, how cycle increase or minimizing, split are adjusted, and when delay value all no longer diminishes, optimize complete.